Quantiferon-TB gold test (QFT-RD1) is a new diagnostic test for latent tuberculosis and a valuable alternative to skin testing. This whole-blood assay measures the production of IFN-  in whole blood upon stimulation by ESAT-6 and CFP-10 and allows distinction of latent M. tuberculosis infection from BCG-induced reactivity. ESAT-6 and CFP-10 are deleted from BCG Region 1 (RD1), not present in most nontuberculous mycobacteria and are highly specific indicators of M. tuberculosis infection. Thus, the aim of this study was to estimate the specificity and sensitivity of a whole blood IFN-γassay employing CFP-10 and ESAT-6, for the detection of M. tuberculosis infection in a clustered high risk elderly population.